Aye, there’s no doubt about it. If you fit a fork slightly too short it can make the bike feel sluggish. My own bike is a bit of a mix match at the moment and the Pike dual position in 130 mode rode crap over (and up) just about everything compared to what it can do in 160 mode. The weird thing is, I’ve fitted offset bushes (M6 difference front and rear) and the fork is now more usable over so much terrain now in 130 mode.
To the OP, I’ve had no problems with mine. The reason I bought dual position was to make them more swappable between bikes but like some folk have said, it won’t make a huge difference to certain gradients when climbing. The bike will feel far faster at full travel on many of the easier climbs you encounter. Sounds odd, but it’s how forks do their thing on bikes when they’re dropped too short beyond what the frame was designed for. I thought I was imagining things on my 2005 Marz all Mountain 2’s but it’s happened on every fork since.